Ditemukan 5 dokumen yang sesuai dengan query
Restu
"Penelitian ini bertujuan untuk mengoptimalkan efektivitas terapi menggunakan radionuklida Lutetium-177 dengan mengukur aktivitas secara akurat di setiap volume anatomi. Penelitian dilakukan untuk menentukan faktor kalibrasi (calibration factor, CF) dan koefisien pemulihan (recovery coefficient, RC), beserta ketidakpastiannya, untuk setiap metode rekonstruksi yang digunakan dalam praktik klinis. Nilai CF merupakan nilai kuantifikasi citra menjadi aktivitas. Penentuan CF dilakukan melalui akuisisi sumber titik. Hasil menunjukkan bahwa rekonstruksi tidak berpengaruh signifikan terhadap nilai CF, sedangkan ketidakpastian akibat peluruhan selama akuisisi berdampak kecil terhadap perbedaan nilai. Nilai RC merupakan faktor koreksi dalam memperkirakan aktivitas yang dipengaruhi oleh efek volume parsial (partial volume effect PVE). Penentuan RC dilakukan dengan akuisisi fantom NEMA-IEC. Pengukuran nilai RC melibatkan variasi beberapa parameter, antara lain pemilihan volume (volume of interest, VOI), jumlah iterasi, dan jenis rekonstruksi. Hasil menunjukan bahwa variasi VOI yang mempertimbangkan cacahan tertumpah (spill-out) menghasilkan nilai RC yang lebih representatif. Pada variasi metode rekonstruksi, jumlah iterasi tidak mempengaruhi nilai RC secara signifikan, sedangkan jenis rekonstruksi memiliki pengaruh yang besar terhadap nilai RC. Ketidakpastian kurva RC akibat ketidakpastian volume dipengaruhi oleh ketidakpastian voksel, resolusi spasial, dan ketidakpastian parameter pencocokan kurva. Berdasarkan analisis gambar dan parameter, hasilnya diperoleh bahwa saturasi dalam rekonstruksi AST dicapai pada volume yang lebih kecil dengan ketidakpastian yang lebih rendah dibandingkan dengan rekonstruksi OSEM, FBP, dan MLEM. Dengan demikian, baik secara kualitatif maupun kuantitatif, rekonstruksi AST memberikan representasi ukuran objek yang lebih baik.
This study aims to optimize the effectiveness of therapy using Lutetium-177 radionuclide by accurately measuring activity in each anatomical volume. The study was conducted to determine the calibration factor (CF) and recovery coefficient (RC) and their uncertainty for each method of reconstruction used in clinical practice. The CF value is the quantification value of the image into activity. CF determination is carried out through point source acquisition. The results show that reconstruction has no significant effect on the value of CF. In contrast, the uncertainty due to decay during acquisition has a small impact on the difference in value. The RC value is a correction factor in estimating activity affected by the partial volume effect (PVE). RC determination is carried out through NEMA-IEC phantom acquisition. The RC value measurement involves various parameters, including : the calculated volume of interest (VOI), the number of iterations, and the type of reconstruction. The results show that the variation of VOI that considers the spill-out results in a more representative RC value. In the various reconstruction methods, the number of iterations does not significantly affect the RC value, while the type of reconstruction greatly influences the RC value. The uncertainty of the RC curve due to volume uncertainty is influenced by voxel uncertainty, spatial resolution, and curve matching parameter uncertainty. Based on image and parameter analysis, the results show that saturation in the AST reconstruction is achieved at a smaller volume with lower uncertainties compared to OSEM, FBP, and MLEM reconstructions. Thus, both qualitatively and quantitatively, the AST reconstruction provides a better representation of the object's size."
Depok: Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia;Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia;Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia;Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia;Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2023
S-pdf
UI - Skripsi Membership Universitas Indonesia Library
Witta Kartika Restu
"Dimetil eter (DME) diproduksi dengan dua metode: (1) metode tidak langsung yang memiliki dua langkah prosedur, pembentukan metanol dari gas sintesis dilanjutkan dehidrasi metanol dan (2) metode langsung yang memiliki satu langkah prosedur yaitu proses pembentukan dimetil eter secara langsung dari gas sintesis. Sintesis langsung dimetil eter dari gas sintesis secara termodinamika lebih berprospek karena memiliki konversi yang lebih tinggi dan secara ekonomi memiliki biaya operasi yang rendah. Penelitian ini bertujuan membuat katalis bifungsi dengan karakteristik kristalinitas tinggi dan luas permukaan besar dengan aktivitas yang tinggi. Katalis yang digunakan adalah logam Cu-Zn sebagai katalis sintesis metanol dan Zeolit Alam Malang teraktivasi (HZAM). Metode preparasi katalis yang digunakan adalah kopresipitasi-sedimentasi dan sol gel-impregnasi. Dilakukan variasi temperatur kalsinasi pada 350, 500, dan 600°C. Pengujian terhadap zeolit alam teraktivasi yang dihasilkan adalah dengan menggunakan karakterisasi BET untuk mengetahui luas permukaan dan karakterisasi XRF untuk mengetahui rasio Si/Al di dalamnya. Pada katalis bifungsi dilakukan karakterisasi BET, XRD, dan XRF. Katalis bifungsi beroperasi pada kondisi tekanan 20 bar dan temperatur 220_C. Hasil uji aktivitas katalis terbaik yaitu pada katalis dengan metode kopresipitasi sedimentasi, menunjukan konversi CO sebesar 34% (% mol), selektivitas dimetil eter sebesar 55% (% mol), dan yield dimetil eter sebesar 19% (% mol).
Dimethyl ether produced using methods (1) Indirect method, synthesis and dehidration of methanol (2) Direct method, synthesis dimethyl ether from syngas. It has higher conversion thermodynamically and lower operating cost. This research aims to make a bifunctional catalyst with some characteristic such as high crystalinity, high surface area, and high activities. Catalyst consists of Cu-Zn metal as synthesis methanol catalayst and activated natural zeolite as dehydration catalyst. Method using in preparation catalyst is coprecipitation sedimentation and sol gel impregnation. Variation is done in calcinations temperature, 350, 500, and 600°C. Activated natural zeolite characterized by BET to know surface area and XRF to know Si/Al ratio. Bifunctional catalyst characterized by BET surface area, XRD, and XRF. Operation condition of bifunctional catalyst is 20 bar and 220°C. Best catalyst activity, catalyst with coprecipitation sedimentation method show CO conversion 34% (% mole), dimethyl ether selectivity 55% (% mole), and yield dimethyl ether 19% (% mole)."
Depok: Fakultas Teknik Universitas Indonesia, 2009
S51826
UI - Skripsi Open Universitas Indonesia Library
Aryanti Prima Restu
"Penelitian ini menganalisis mengenai program tata kelola destinasi pariwisata atau lebih dikenal dengan sebutan Destination Management Organization yang dilakukan oleh Kementerian Pariwisata. Apakah program tersebut berhasil dalam perannya dalam meningkatkan perekonomian daerah dan memeratakan manfaat ekonomi dari pariwisata kepada masyarakat lokal. Dengan menggunakan analisis kovarians untuk membandingkan koefisien Gini antara kabupaten/kota dengan program DMO dengan kabupaten/kota tanpa program DMO pada saat sebelum dan setelah pelaksanaan program didapatkan hasil bahwa tidak terdapat perbedaan yang signifikan antara kedua kelompok tersebut. Namun secara deskriptif terdapat indikasi bahwa program DMO akan mengurangi ketimpangan pendapatan di kabupaten/kota yang mendapatkan program tersebut.
This study aim to analyze whether the Destination Management Organization program conducted by the Ministry of Tourism is successful in its role increasing the local economy and distributing the economic benefits of tourism equally to the local communities. Using analysis covariance to compare the Gini coefficient between districts cities with DMO program with the district city without DMO program before and after the implementation of the program, this study showed that there was no significant difference between the two groups. However descriptively there are indications that the DMO program will reduce inequality in districts cities with the program."
Depok: Universitas Indonesia, 2017
T47005
UI - Tesis Membership Universitas Indonesia Library
Muhammad Restu
"Diosphyros celebica Bakh., also known as Sulawesi ebony, is an endemic to central and northern Sulawesi. Information about pollen dispersal patterns of D. celebica have not been previously investigated. This study was aimed to determine pollination type, percentage of selfing and outcrossing, as well as distance of pollen dispersal of D. celebica. This study was conducted at experimental forest of Universitas Hasanuddin, Maros District, South Sulawesi Province, Indonesia. One hundred and sixty six individuals of D. celebica consisted of adult trees and seedlings were analyzed in this study. Ninety four adult trees were selected to become parent trees. The trees were mapped with GPS coordinates . All samples were genotyped using four SSR markers loci. Parental analysis and determination of pollen dispersal patterns were carried out using Cervus 3.0.3. Results indicated that the evaluated markers were effective for assigning candidate of male parents to all evaluated seedlings. Donated pollens could come from male parents in any directions relative to female parent positions. Pollen dispersal pattern showed outcrossing pollination among different male parents (pollen donated trees). The results indicated that seeds were produced predominatly by outcrossing. Pollen dispersal reached up to 166 m. Pollen related processes were linked through female parents, pollinators availability and ecological environment. Simultaneous use of progeny genotyping, spatially explicit analysis of environmental variables and outcomes of plant–animal interactions, were the key elements for an expanded approach to gene flow analysis considering dispersal via pollen and seeds. Research on pollen dispersal of D. celebica should be carried out in other forest types, such as mixed forest and highland forest."
Bogor: Seameo Biotrop, 2017
634.6 BIO 24:3 (2017)
Artikel Jurnal Universitas Indonesia Library
Muhammad Restu
"Diosphyros celebica Bakh., also known as Sulawesi ebony, is an endemic to central and northern Sulawesi. Information about pollen dispersal patterns of D. celebicahave not been previously investigated. This study was aimed to determine pollination type, percentage ofselfing and outcrossing, as well as distance ofpollen dispersal of D. celebica.This study was conducted at experimental forest of Universitas Hasanuddin, Maros District, South Sulawesi Province, Indonesia. One hundred and sixty six individuals ofD. celebicaconsisted ofadult trees and seedlings were analyzed in this study. Ninety four adult trees were selected to become parent trees. The trees were mapped with GPS coordinates. All samples were genotyped using four SSR markers loci. Parental analysis and determination ofpollen dispersal patterns were carried out using Cervus 3.0.3.Results indicated that the evaluated markers were effective for assigning candidate ofmale parents to all evaluated seedlings. Donated pollens could come from male parents in any directions relative to female parent positions. Pollen dispersal pattern showed outcrossing pollination among different male parents (pollen donated trees). The results indicated that seeds were produced predominatly by outcrossing. Pollen dispersal reached up to 166 m. Pollen related processes were linked through female parents, pollinators availability and ecological environment. Simultaneous use ofprogeny genotyping, spatially explicit analysis ofenvironmental variables and outcomes ofplant–animal interactions were the key elements for an expanded approach to gene flow analysis considering dispersal via pollen and seeds. Research on pollen dispersal of D. celebica should be carried out in other forest types, such as mixed forest and highland forest."
Bogor: Seameo Biotrop, 2017
634.6 BIO 24:3 (2017)
Artikel Jurnal Universitas Indonesia Library